Automatic assembling method and apparatus for assembling photographic film cassettes

ABSTRACT

Automatic assembling method and apparatus using a plurality of pallets on a conveyer belt for assembling photographic film cassettes, or the like. Each pallet has a secondary work holder and a primary work holder. Parts of a secondary assembly are sequentially fed to the secondary work holder and are assembled into the secondary assembly in the secondary work holder. The secondary assembly and other parts of a primary assembly are sequentially fed to the primary work holder and are assembled into the primary in the primary work holder.

This is a divisional of application Ser. No. 08/829,141, now U.S. Pat.No. 6,279,220, filed Mar. 31, 1997, which is a continuation ofapplication Ser. No. 08/233,261, now abandoned, filed Apr. 26, 1994, thedisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an automatic assembling method, andmore particularly to a method of automatically assembling a photographicfilm cassette, or the like, and an apparatus for practicing the method.

2. Description of the Related Art

Photographic film of the 135 type, contained in a cassette, as among themost popular formats of photographic film. A known 135 photographic filmcassette has a cassette shell constituted of a cylindrical body formedof a thin metal sheet and two caps fitted thereon. The cassette shellhas a spool contained therein on which photographic film is wound in aform of a roll. To assemble this photographic film cassette, severalmethods are known. For example, U.S. Pat. No. 4,614,019 (correspondingto Japanese Patent Publication No. 2-691) discloses a process of windingthe photographic film on the spool, and then assembling the cassette ina darkroom: U.S. Pat. No. 4,080,711 (corresponding to Japanese PatentPublication No. 60-48748) discloses a process of bringing the assembledcassette shell into the darkroom, disassembling the cassette shell forinsertion of the photographic film, inserting the photographic filmwound on the spool, and then assembling the cassette shell.

U.S. Pat. No. 4,834,306, U.S. Pat. No. 4,846,418 and EuropeanPublication EP-A2 0 406 815 (corresponding to Japanese Patent Laid-openPublication No. 3-37645), each disclose a photographic film cassette inwhich a cassette shell is constituted of parts formed from resin, androtation of a spool causes a leader of the photographic film to exit tothe outside of the cassette. Such a leader-advancing cassette isdifferent from conventional photographic film cassettes because theleader of the photographic film is fully contained within the cassetteboth before exposure and after exposure. Such a cassette is advantageousin that the photographic film is reliably protected from accidentalexposure to ambient light, and in that the cassette is easily handled.

Such a leader-advancing cassette includes elements not utilized inconventional cassettes. As disclosed, for example, in U.S. Pat. No.4,834,306 (corresponding to Japanese Patent Laid-open Publication No.1-306845) and U.S. Pat. No. 5,049,912, a light-shielding shutter membermay be mounted openably in a photographic film passage port of this typeof film cassette for protecting the inside from ambient light. Or avisual indicator member may be incorporated in such a cassette, toappear externally for indicating the exposed condition of thephotographic film. However, production of such a leader-advancingcassette has many inherent problems due to the increase in the number ofthe parts. Particularly when the cassette shells must be assembled ordisassembled in a darkroom, the assembling operation is so complicatedthat production efficiency is difficult to increase. In such a case,even an automated assembling machine does not reliably increaseproduction efficiency.

The problems are more complicated for a photographic film cassettewherein a spool is an assembly constituted of a pair of flangesforce-fitted of the spool core, and the spool assembly is mounted in oneshell half before the other shell half is joined therewith. This isbecause an independent assembling process for assembling the spoolassembly is necessary before a primary assembling process of the filmcassette, wherein the spool assembly, the shutter plate and other partsare mounted into the cassette. In such a case, there are at least twoassembling lines and at least a transfer conveyor for connecting the twolines. Therefore, the mechanism of the conventional system arecomplicated. The need for transferring works between the lines increasesthe occurrence of problems. The same problem as described above couldgenerally arise in other automatic assembling systems, where a secondaryassembly should be incorporated into a primary assembly.

On the other hand, a constant tact intermittent transport linear basemachine for moving an endless conveyor member such as a belt or a chainperiodically by a constant amount, is known, for example, from JapanesePatent Laid-open Publication 4-209121, wherein pallets are secured tothe endless conveyor member. When assembling works by using such aconstant tact intermittent transport linear base machine, if positionsof the pallets get out of order because of jamming of the works, stoppositions of the pallets must be readjusted to restore the accuracy ofassemblage. Readjustment requires a great deal of time so that theefficiency of the assembly process decreases.

Conventional constant tact intermittent linear base machines furtherhave a problem in that the pallet must be decoupled from and coupled tothe conveyor to be fed back to the assembling line, through a feed backline, after the completion of assemblage on that pallet. Thedecoupling-coupling operations often cause problems especially in a highspeed tact system.

SUMMARY OF THE INVENTION

In view of the above problems, an object of the present invention is toprovide an automatic assembling method, and an apparatus for thatmethod, which enables a high efficiency assembly operation, even when asecondary assembly must be assembled into a primary assembly in aprimary assembling process, while the secondary assembly is assembled inan independent secondary assembling process.

Another object is to provide an automatic assembling apparatus whichuses a constant tact intermittent transport linear base machine, buteliminates deviation of pallets and trouble in decoupling and couplingof the pallet being conveyed at short intervals.

A further object of the present invention is to provide an automaticassembling method for assembling a cassette shell of a film cassetteinclusive of a spool assembly in a single assembling line.

To achieve the above and other objects, according to the presentinvention, each of a plurality of integrally formed pallets has asecondary work holder and a primary work holder which are arranged inthe same desired positions. Parts of a secondary assembly aresequentially fed to the secondary work holder and are assembled into thesecondary assembly in the secondary work holder in each pallet duringconveying the pallets. The secondary assembly and other parts of aprimary assembly are sequentially fed to the primary work holder and areassembled into the primary assembly in the primary work holder in eachpallet during conveying the pallets.

Therefore, it is unnecessary to provide a secondary assembling line forassembling the secondary assembly separately from a primary assemblingline for the primary assembly. Because of the single assembling line, itis unnecessary to provide interconnecting devices such as asynchronizing device and a buffer conveyor, which would otherwise benecessary for connecting the primary and secondary assembling lines.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the present invention will becomeapparent from the following detailed description of the preferredembodiments when read in connection with the accompanying drawings,wherein like reference numerals designates like or corresponding partsthroughout the several views, and wherein:

FIG. 1 is an exploded perspective view illustrating an example of aleader-advancing film cassette;

FIG. 2 is an explanatory perspective view of a pallet utilized forassembling a spool assembly and a cassette shell of the leader-advancingfilm cassette shown in FIG. 1, according to a preferred embodiment ofthe apparatus;

FIG. 3 is a schematic side view of a pallet conveyor;

FIG. 4 is a schematic top plan view illustrating the pallet conveyorshown in FIG. 3 and an assembling unit of the preferred embodiment;

FIG. 5 is an enlarged top plan view of the pallet positioned on thepallet conveyor by a pallet positioning unit of the preferredembodiment; and

FIG. 6 is a top view of the positioning unit of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a photographic film cassette to be assembled by acassette assembling apparatus according to a preferred embodiment of thepresent invention as shown in FIGS. 2-6. A spool assembly 12 iscontained in a cassette shell 10 constituted of a pair of shell halves 7and 8 molded from resin. Ridges 15 are formed on the inside of the shellhalves 7 and 8. When photographic film 24 is wound around the spoolassembly 12 and contained within a chamber defined between the shellhalves 7 and 8, the ridges 15 are in contact with the outermost turn ofthe photographic film 24 to prevent the roll of the photographic film 24from loosening. When the spool assembly 12 is rotated in the directionto unwind the film 24, clockwise in FIG. 1, the roll of the photographicfilm 24 is also rotated clockwise. A separator claw 17 is formed insideof shell half 8. During rotation of the roll of the photographic film24, a leading end of the photographic film abuts on the separator claw17, which separates the leading end from the roll of the film 24.

Port walls 7 a and 8 a are formed on the shell halves 7 and 8,respectively. When the shell halves 7 and 8 are joined together, theport walls 7 a and 8 a define a photographic film passage port 19. Ashutter 14 is rotatably mounted in a cylindrical cavity formed by a pairof semi-cylindrical recesses 23 formed inside the port walls 7 a and 8a. Both ends of the shutter 14 are provided with rotary shaft portions14 a to be borne between the port walls 7 a and 8 a, so that the shutter14 is rotatable about an axis which is parallel to the spool assembly12. An end of the shaft portions 14 a has a key 16, which extendsthrough a hole formed in the cassette shell 10. When an opener member 18is fitted on the key 16 and rotates the key 16, the shutter 14 isrotated between positions of blocking and opening a film passage 19formed between the port walls 7 a and 8 a.

The spool assembly 12 is constituted of a spool core 12 a and a pair offlanges 12 b fitted on the spool core 12 a. The photographic film 24 iswound on the spool core 12 a between the flanges 12 b. Both ends of thespool assembly 12 extend through faces of the cassette shell 10, and areprovided with keys 13. The keys 13 are used for engagement with a drivemember for rotating the spool assembly 12 in a known manner. A notch 13a is formed in one of the keys 13, for externally indicating therotational position of the spool assembly 12. This indication isnecessary for inserting the film trailer 24 a into a slot 20 formedalong the spool core 12 a.

Inside the slot 20 are arranged two retaining claws 21 and aslip-preventive ridge which is not shown but extends in the directionopposite to, and are disposed between, the retaining claws 21. The rightside of the slot 20 is adapted to receive the film trailer 24 a. Thefilm trailer 24 a has a pair of retaining holes 25 formed therein, whichare engageable with the retaining claws 21. The slip-preventing ridgepresses the trailer end 24 a in the direction opposite to projecting ofthe retaining claws 21, so that the holes 25 are maintained engaged withthe retaining claws 21, even if a force tending to pull the photographicfilm 24 from the slot 20 should be applied to the trailer 24 a. Thetrailer 24 a is further provided with a pair of pick-up holes 26 whichare disposed outside the pair of retaining holes 25 in the lateraldirection of the film 24. The pick-up holes 26 are used for insertingthe film trailer 24 a into the slot 20 with a jig.

FIG. 2 illustrates a pallet 30 utilized for assembling theabove-described photographic film cassette. The pallet 30 has a shellholder 31 for holding the one shell half 8, hereinafter referred to as alower shell half 8, and a spool holder 32 for holding the spool assembly12. The pallet 30 also has a pair of positioning pins 33 utilized forpositioning the pallet 30 in respective assembling stations, as will bedescribed in detail below.

The spool holder 32 has a flange accepting recess 32 a and a spool coreaccepting hole 32 b formed therein. After the flange 12 b is positionedin the recess 32 a, the spool core 12 a is inserted in the hole 32 b,while force-fitting the spool core 12 a through the flange 12 b.Thereafter, the other flange 12 c is force fitted on the opposite upperend of the spool core 12 a, completing the spool assembly 12. The shellholder 31 is secured to the pallet 30, and has a recess 31 a formedtherein, whose inside surface corresponds to the outward form of thelower shell half 8. After the lower shell half 8 is placed in the shellholder 31, the spool assembly 12 is pulled off the spool holder 32 andis placed in the lower shell half 8. The other or upper shell half 7 isthen joined to the lower shell half 8 to complete the cassette shell 10.Finally, the complete cassette shell 10 is removed from the shell holder31.

The above-described spool assembling operations and the assemblingoperations for the cassette shell 10 are performed by an assembling unitconstituted of a series of pick-and-place devices, as will be describedbelow with respect to a preferred embodiment.

The pallets 30 are successively conveyed by a pallet conveyer 40, forexample, as shown in FIGS. 3 and 4. The pallet conveyer 40 isconstituted of an endless belt 41 circulating in a horizontal attitudearound pulleys 42 and 43 whose rotary shafts 42 a and 43 a extend inparallel with each other in a horizontal plane. This construction of apallet conveyer requires only a simple drive mechanism. The endless belt41 has a plurality of pallet spacers 44 mounted on the bearing surfacethereof. The pallet spacers 44 are spaced equally in the longitudinaldirection of the belt 41 by a distance slightly longer than the lengthof the pallets 30. The pallet spacers 44 are rectangular ridgesprojecting from the bearing surface of the belt 41, which confine thepallets 30 at the leading and trailing ends thereof in the conveyingdirection or the longitudinal direction of the pallets 30 during theconveying. Instead of the rectangular ridges 44, pallet spacers may beformed by pins which are adopted to be loosely engaged in holes whichmay be formed in the bottom of pallets.

As shown in FIG. 4, the shaft 43 a of the puller 43 is coupled to aconstant angle rotation unit 45 for controlling constant tactintermittent transport of the endless belt 41. The unit 45 is driven bya cam shaft 46 to cause the pulley 43 to rotate intermittently bythrough a constant incremental angle. Thereby, the pallets 30 areperiodically advanced by a constant amount through the endless belt 41.The cam shaft 46 is driven by a drive motor 48 through a transmissionbelt 47.

A plurality of pick-and-place devices 50 are disposed along an upperpath of the endless belt 41 of the pallet conveyer 40 in every otherstop position of the pallets 40, to assemble the respective parts of thecassette shell 10, such as the shell halves 7 and 8, the shutter plate14, the spool core 12 a and the flanges 12 b and 12 c, appropriately inthe holders 31 and 32 of the pallets 30. In each pick-and-place device50, a designated part is picked up by one end of an arm 50 a, andsimultaneously the same part is mounted on an appropriate place by theother end of the arm 50 a.

A pick-and-place device 52, which is disposed at a last position in thepallet conveying direction, removes the complete cassette shell 10 fromthe shell holder 31 and discharges it from the assembling line, that is,the upper path of the endless belt 41. The pick-and-place device 52 alsohas an arm 52 a which operates in the same way as the arms 50 a. Thepick-and-place devices 51 and 52 are also driven by the cam shaft 46through cam members 50 b, 50 c, 52 b and 52 c, respectively, in aconventional manner.

Parts feeders 51 are disposed beside the pick-and-place devices 50, eachfor feeding the designated parts one after another to the associatedpick-and-place device 50. Of course, no parts feeder is allocated to oneof the pick-and-place devices 50 which serves to mount the completespool assembly 12 into the lower shell half 8. Hereinafter, the stoppositions of the pallets 30 corresponding to the pick-and-place devices50 and 52 will be referred to as assembling stations S1 to S8.

As shown in FIG. 5, pallet guide fences 53 and 54 are provided onlateral sides of the endless belt 41 along the upper path of the belt41, to limit lateral movement of the pallets 30 on the endless belt 41.The pallet guide fences 53 and 54 are mounted on an upper surface of aguide base 55, on which the endless belt 41 is guided in the horizontalstate. Along a lower path of the endless belt 41 and around the pulleys42 and 43, anti-drop guide rails 56 and 57 are provided for preventingthe pallets 30 from dropping off the endless belt 41, as is shown inFIG. 5. The anti-drop guide rails 56 and 57 are mounted to a guide base58. The anti-drop guide rails 56 are constituted of a pair of fencesdisposed along the lateral sides of the endless belt 41 and having hooks56 a which catch the lateral edges of the pallets 30. Therefore, thepallets 30 may not drop down in spite of their weight. The anti-dropguide rails 57 have the same construction and function as the anti-dropguide rails 56. The lower path of the endless belt 41 functions as afeed back line for feeding empty pallets 30 back to the assembling line.

Because the pallets 30 are not secured to the endless belt 41, but areremovably held by the pallet spacers 44 and the guide fences 53 and 54,maintenance and positioning of the pallets 30 are each independentlyadjustable in individual assembling stations. By providing the anti-dropguide rails 56 and 57, the pallets 30 may be conveyed cyclically on theendless belt 41 without the need for decoupling the pallets 30 from theendless belt 41 and then coupling the same to the endless belt 41.Therefore, a high speed of transport or short interval between transportsteps may be achieved with reliability.

As shown in FIGS. 5 and 6, a positioning unit 60 is disposed inassociation with each pick-and-place devices 50 and 52. The positioningunit 60 has a lateral positioning plate 61 and a longitudinalpositioning plate 62. The lateral positioning plate 61 is mounted to aguide plate 63 to be movable in the lateral direction of the pallet 30.The lateral positioning plate 61 is secured to a bracket 65 having a camfollower 66 secured thereto. The cam follower 66 contacts an eccentriccam 67, and a coiled spring 68 suspended between the bracket 65 and theguide 63 urges the cam follower 66 toward the cam 67. Accordingly, thelateral positioning plate 61 is urged away from the pallet 30. The cam67 is driven through the cam shaft 46 to rotate at an angle of 180degrees in each step.

The longitudinal positioning plate 62 is mounted to a guide plate 70 tobe movable in the lateral direction of the pallet 30. The lateralpositioning plate 62 is secured to a bracket 71 having a cam follower 72secured thereto. The cam follower 72 contacts an eccentric cam 73, and acoiled spring 75 suspended between the bracket 71 and the guide plate 70urges the cam follower 72 toward the cam 73. Accordingly, longitudinalpositioning plate 62 is urged toward the pallet 30. The eccentric cam 73is also driven through the can shaft 46 to rotate at an angle of 180degrees in each step.

The longitudinal positioning plate 62 has a pair of symmetrical slopes76 spaced from each other in the longitudinal direction of the endlessbelt 41, such that the slopes 76 are brought into tangential contactwith the positioning pins 33 of the pallet 30 to push the pins 33 towardeach other when the longitudinal positioning plate 62 is moved towardthe pallet 30.

While the pallets 30 are conveyed on the endless belt 41 by one step,that is, from one stop position to the next, the cam shaft 46 causes theeccentric cams 67 and 73 to rotate by one step, that is, by 180 degrees.Each time the pallets 30 are stopped at the respective assemblingstations S1 to S8, the eccentric cams 67 and 73 are set in the positionsshown in FIG. 5, wherein the cam 67 pushes the cam follower 66 to movethe bracket 65 against the force of the spring 68 and thus move thelateral positioning plate 61 toward the pallet 30 into a predeterminedposition, as is shown by solid line in FIG. 6. Concurrently, thelongitudinal positioning plate 62 is moved toward the pallet 30 underthe force of the spring 75, as is shown by solid line in FIG. 6.Thereby, the pallet 30 is pushed against the lateral positioning plate61, to be positioned in the lateral direction.

Because the positioning pins 33 are pushed toward each other by theslopes 76 while the longitudinal positioning plate 62 is moved towardthe pallet 30, the pins 33 are centered on the symmetrical axis of theslopes 75, so that the pallet 30 is positioned in the longitudinaldirection. While the pallets 30 are advanced from one assembling stationto another, the eccentric cams 67 and 73 are rotated by two steps, thatis, by 360 degrees, so that the positioning plates 61 and 62 make onereciprocation to be retracted from and then moved toward the pallet 30,as is indicated by arrows and phantom lines in FIG. 6.

The assembling operations of the cassette shell 10 are performed, forexample, in the following sequence.

The respective pallets 30 are periodically advanced by the palletconveyer 40 to be seriatim fed to the respective assembling stations S1to S8, as is shown in FIGS. 3 and 4. In the first assembling station S1,the pick-and-place device 50 mounts the lower shell half 8 in the shellholder 31 of the pallet 30, as is shown in FIG. 2. Next, the shutter 14is mounted in the semi-cylindrical recess 23 of the lower shell half 8in the second assembling station S2. In the third assembling station S3,the flange 12 b is set in the flange accepting recess 32 a of the spoolholder 32 of the pallet 30. In the fourth assembling station S4, thespool core 12 a is fitted in the spool core accepting hole 32 b of thespool holder 32, thereby force-fitting the flange 12 b on one end of thespool core 12 a. In the fifth assembling station S5, the flange 12 c isfitted on the other end of the spool core 12 a which is still fitted inthe spool core accepting hole 32 b. In the sixth assembling station S6,the complete spool assembly 12 is pulled off the spool holder 32 andmounted in the lower shell half 8 held in the shell holder 31. In theseventh assembling station S7, the pick-and-place device 50 joins theupper shell half 7 to the lower shell half 8, through ultrasonic weldingor the like, in the shell holder 31, to complete the cassette shell 10.In the last station S8, the pick-and-place unit 52 removes the cassetteshell 10 from the shell holder 31 to transfer the shell 10 to anotherline. The pallet conveyer 40 feeds the empty pallet 30 back to the firstassembling station S1 The control and activation of various functionswith pick-and-place units 52 is well known.

In alternative, it is possible to first perform assembling of the spoolassembly 12 in the side of the spool holder 32, and thereafter startassembling in the side of the shell holder 31. The flanges may besecured to the spool core through hooking, caulking, cementing or thelike. It is, of course, possible to provide more than either stations soas to assemble a cassette shell having a larger number of parts than thecassette shell shown in FIG. 1, such as disclosed in U.S. Pat. No.5,049,912.

As described so far, according to the present invention, each pallet hasa secondary work holder, such as a spool holder, besides a primary workholder, such as a shell holder, so that parts of a secondary assembly,such as a spool assembly, are sequentially assembled in the side of thesecondary work holder, and parts of a primary assembly, such as acassette shell, which includes the secondary assembly as one of itsparts, are sequentially assembled in the primary work holder, while thepallet is conveyed along a single assembling line.

Therefore, it is unnecessary to provide a secondary assembling line forassembling the secondary assembly separately from a primary assemblingline for the primary assembly. Because of the single assembling line, itis also unnecessary to provide interconnecting devices such as asynchronizing device and a buffer conveyer, which would otherwise benecessary for connecting the primary and secondary assembling lines.Therefore, the assembling apparatus of the present invention may besimple in construction and facilitates increasing assembling speed andefficiency. The assembling apparatus of the present invention may alsobe constructed at reduced expense as it requires merely a single drivemotor and a constant angle rotation unit for transporting palletsintermittently at a constant tact or pitch. It also requires merely onetype of pallet. Moreover, malfunctions may be reduced because the needfor handing the workpieces is reduced. The pallets of the preferredembodiment are integrally formed, i.e., are assembled from one or morepieces in a single unitary structure.

While the present invention has been described with respect to apreferred embodiment for automatic assembling of the cassette shell 10,the present invention is applicable to automatic assembling of any kindof article wherein a secondary assembly should be incorporated in aprimary assembly.

Also, it will be apparent to one skilled in the art that various othermodifications can be made to the disclosed embodiment without departingfrom the scope of the invention as defined by the appended claims.

What is claimed is:
 1. An automatic assembling apparatus for assemblinga primary assembly including a secondary assembly as one part thereof,said apparatus comprising: at least two rotary shafts extending inparallel with each other in a horizontal plane; an endless belt disposedaround said rotary shafts; a plurality of integral formed pallets havingthe same construction; a holding member for removably holding saidpallets on said endless belt in alignment with a longitudinal directionof said endless belt; a driving device for driving said endless beltthrough said rotary shafts to convey said pallets cyclically andintermittently at regular intervals by a constant pitch; primary andsecondary work holders mounted on one side of each of said pallets atcorresponding positions of each of said pallet; first feeding andassembling devices for sequentially feeding parts of said secondaryassembly to said secondary work holder of each of said pallets andassembling said parts into said secondary assembly in said secondarywork holder; second feeding and assembling devices for sequentiallyfeeding said secondary assembly and other parts of said primary assemblyto said primary work holder of each of said pallets and assembling saidsecondary assembly and said other parts into said primary assembly insaid primary work holder; and a positioning device for individuallyadjusting the position of the pallets in relation to each of the firstand second feeding and assembling devices by moving the pallets withrespect to a path of the endless belt in the longitudinal direction anda transverse direction while the pallets are held on the endless belt.2. An automatic assembling apparatus as recited in claim 1, wherein saidfirst and second feeding and assembling devices are disposed inpredetermined stations which are arranged along an upper path of saidendless belt in a predetermined sequence of assembling.
 3. An automaticassembling apparatus as recited in claim 2, wherein said holding membersinclude a plurality of projection members disposed on a palletsupporting side of said endless belt to be loosely engaged with saidpallets, guide fences disposed along said endless belt on later al sides of said pallets, and anti-drop guide rails disposed below a lowerpath of said endless belt and around both corners between said upper andlower paths of said endless belt.
 4. An automatic assembling apparatusas recited in claim 3, wherein said at least two rotary shafts are twoshafts disposed in said corners of said endless belt, and one of saidrotary shafts is coupled to said driving device.
 5. An automaticassembling apparatus as recited in claim 4, wherein said first andsecond feeding and assembling devices are driven by said driving devicein synchronism with each other.
 6. An automatic assembling apparatus asrecited in claim 2, wherein said positioning device comprises a pair ofpositioning plates disposed on lateral sides of said pallets and meansfor moving said positioning plates in a transverse direction of saidendless belt such that a first one of said positioning plates contactone lateral side of said one pallet at a predetermined position, while asecond one of said positioning plates pushes said one pallet againstsaid first positioning plate, thereby to position said one pallet in thetransverse direction, and wherein said second positioning plate has apair of symmetrically sloped portions which are spaced from each otherin the longitudinal direction of said endless belt, said secondpositioning plate pushing said one pallet at said slopes, thereby toposition said one pallet in the longitudinal direction.
 7. An automaticassembling apparatus as recited in claim 6, wherein said sloped portionsare brought into tangential contact with a pair of pins which aremounted on each of said pallets and are aligned in the longitudinaldirection.
 8. An automatic assembling apparatus as claimed in claim 1,wherein said primary assembly is a cassette shell of a photographic filmcassette which comprises a pair of shell halves and a spool assemblymounted between said shell halves, and said secondary assembly is saidspool assembly, said spool assembly comprising a spool core and a pairof flanges secured to said spool core.